After emailing a bit with Brendan Nyhan about this post, I think I’d better back off my optimism that Barack Obama might be able to put some northern plains states in play. I’d been basing that on (a) the theory that a lot of Democratic Senators get elected in those states notwithstanding the party’s usually poor presidential performance in that region, and (b) Obama’s pretty good polling results in Survey USA’s state-by-state surveys.
To make a long story short, I think I’ve been overestimating the orthodoxy of the Senators in question. I knew Ben Nelson was one of the furthest-right Senate Democrats, but by Poole-Rosenthal’s measures Max Baucus turns out to be not just right-of-average but actually the second-most-conservative Democratic Senator and then Dorgan, Conrad, and Johnson are all pretty conservative, too. Combine that with Obama’s record on guns, and I think the chances of a breakthrough look much worse than I’d once thought.